1Department of Psychiatry CB# 7160, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. cort_pedersen@med.unc.edu

Abstract

We review recent discoveries that implicate oxytocin in the intergenerational transmission of similar levels of maternal behavior and acute stress responses in female rats. First, ICV-infused oxytocin antagonist decreased the display by nursing dams of pup-licking (PL) and arched-back nursing (ABN), but not other components of maternal behavior, and increased maternal self-grooming suggesting that oxytocin may shift the balance of oral grooming by dams away from themselves and toward pups. Second, oxytocin receptor concentrations in areas of the adult brain where oxytocin stimulates maternal behavior or diminishes anxiety and adrenal axis responses to acute stress were positively related to PL-ABN received during infancy. Third, oxytocin and oxytocin antagonist treatments of pups on postnatal days 2-10, respectively increased and decreased PL by the treated rats when adult and themselves nursing dams. This indicates that oxytocin activity in female pups, which may be regulated by PL-ABN received from their mothers, influences their adult levels of PL. These three lines of evidence suggest that oxytocin selectively enhances PL-ABN by rat dams, which then increases oxytocin activity in female pups and, thereby, facilitates their expression of central oxytocin receptors (and perhaps other aspects of central oxytocin systems) and, consequently, their adult PL-ABN frequencies and acute stress responses.